Improvement in door-springs



UNITED STATES PATENT OFFICE.

ALEXANDER ANDERSON, OF LONDON, CANADA, ASSIGNOR TO JAMES D.V

MILLIKEN, OF CHICAGO, ILLINOIS.

IMPROVEMENT IN DOOR-SPRINGS.

Specification forming part of Letters Patent No. 157,565, dated December 8, 1874; application filed February 16, 1874.

To all whom it may concern y Be it known that I, ALEXANDER ANDER- SON, of London, in the county of Middlesex and Dominion of Canada, machinist, have invented certain Improvements in Door-Springs, of which the following is a speoilication:

This invention relates to the mechanism by means of which I ain enabled to utilize the elasticity of a rubber strap as a door-spring, and to adjust the strength or force of the same 5 and the invention consists in applying to the jamb of the door a bracket extending out a short distance horizontally, terminating in an eye, which is fitted abovewith a erown-ratchet wheel, and applying to the lintel above a socket-piece to receive the upper end ot' a short shaft provided below with a thumbpiece and above the crown-ratchet with a key or pawl. To this shaft is attached one end of an india-rubber strap, the other end of which is affixed to the door. By turning the thumb-shaft the strap is wound thereon and brought to any required tension. Vhen the door is swung open the rubber strap stretches to allow it, and by its retractionJ closes it when released.

In the accompanying drawing, which forms a part of this specitication, Figure l is a side view of a portion of a door havingthis invention applied. Fig. 2 is a view of the apparatus detached and upon a larger scale. Fig. 3 is a section on no x of Fig. 2.

Like letters indicate like parts in all the figures.

In said drawing, A is the door, which opens backward from the view. B is the jamb, and

C the lintel. D is the bracket attached to the jamb, and havingthe crown-ratehetE. F is the socket-piece secured to the lintel. Gis the thumb-shaft, passing up through the crownratchet and entering the socket. This shaft is furnished with the thumb-piece g and the key or pawl e. H is the rubber strap attached to and wound about the shaft at one end, and secured to the door at the other. To allow the shaft to be placed in situ, a slot, cl, is cnt in the rim of the bracket-eye to allow of the passage of the key or pawl e.

The parts being assembled together, as shown in the drawing, the operation is as fol lows: The rubber strap is adjusted-either slackened or tightened-to the required tension by pressing up the shaft within the socket until the pawl e is above the teeth of the ratchet, when it may be turned in either direction and locked in the required position by drawing it down until the pawl again engages the teeth. The door, when swung open, stretches the strap, which, retracting, closes it again.

The adjust-ability of this spring proves a great convenience, as the door may be so fixed that it will just close itselfwithout slainming violently, as some contrivances cause it to do.

If the door is swung open beyond a certain distance it will remain open by the strap setting against the hinge.

I do not claim, broadly, the use of a crownratchet in connection with a door-spring for the purpose of keeping up,77 as I am aware this is old; but

Having described my invention, I claim as new and desire to secure by Letters Patent- The adjustable door-spring, consisting of the bracket D having crown-ratchet E, and the thumb shaft G provided with pawl c and socket F, connected one to the jamb the other to the lintel, andthe rubber strap H connected` to the shaft and the door, substantially as specified, for the purpose set forth.

ALEXR. ANDERSON. 

